U.S. patent application number 14/415212 was filed with the patent office on 2015-07-09 for device for guiding a surgical instrument into position on a bone-anchor element including a means for realigning a link rod with the anchor element, and related system of surgical instruments.
This patent application is currently assigned to SAFE ORTHOPAEDICS. The applicant listed for this patent is SAFE ORTHOPAEDICS. Invention is credited to Dominique Petit.
Application Number | 20150190183 14/415212 |
Document ID | / |
Family ID | 47137839 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150190183 |
Kind Code |
A1 |
Petit; Dominique |
July 9, 2015 |
Device for Guiding a Surgical Instrument Into Position On a
Bone-Anchor Element Including A Means For Realigning a Link Rod
With the Anchor Element, and Related System of Surgical
Instruments
Abstract
A device for guiding a surgical instrument having one end for
coupling to the head of a bone anchor element and a longitudinal
channel, the head of the bone anchor element having a tapped
longitudinal recess intended for receiving a screw cap, said
longitudinal recess leading into a transverse channel capable of
receiving a link rod, characterised in that said guiding device
includes a rod for guiding the surgical instrument, with a
longitudinal axis A, having one end comprising two semi-tubular
tabs in which the outer section matches the inner section of said
longitudinal recess and in which the inner section is at least
equal to the diameter of the link rod, the cross-section of the
guiding device being always smaller than the section of the
longitudinal channel of the surgical instrument in order to allow
the insertion and the removal of said device in the distal
direction.
Inventors: |
Petit; Dominique; (Verton,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAFE ORTHOPAEDICS |
Eragny Sur Oise |
|
FR |
|
|
Assignee: |
SAFE ORTHOPAEDICS
Eragny Sur Oise
FR
|
Family ID: |
47137839 |
Appl. No.: |
14/415212 |
Filed: |
July 18, 2013 |
PCT Filed: |
July 18, 2013 |
PCT NO: |
PCT/FR2013/051741 |
371 Date: |
January 16, 2015 |
Current U.S.
Class: |
606/86A |
Current CPC
Class: |
A61B 17/7083 20130101;
A61B 17/7086 20130101; A61B 17/7091 20130101 |
International
Class: |
A61B 17/70 20060101
A61B017/70 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 19, 2012 |
FR |
1257003 |
Claims
1-11. (canceled)
12. A device for guiding a surgical instrument having one end for
coupling to the head of a bone anchor element and a longitudinal
channel, the head of the bone anchor element having a tapped
longitudinal recess configured to receive a screw cap, said
longitudinal recess leading into a transverse channel configured to
receive a link rod, said guiding device comprising a rod for
guiding the surgical instrument, with a longitudinal axis A, having
one end comprising two semi-tubular tabs in which the outer section
matches the inner section of said longitudinal recess and in which
the inner section is at least equal to the diameter of the link
rod, the cross-section of the guiding device being always smaller
than the section of the longitudinal channel of the surgical
instrument in order to allow the insertion and the removal of said
device in the distal direction.
13. The guiding device according to claim 12, wherein the
semi-tubular tabs have a cross-section that fits into the volume
defined between the tapped inner wall of said longitudinal recess
and the plane parallel to the median longitudinal plane, crossing
the surface of the link rod when the latter is positioned in said
transverse channel.
14. The guiding device according to claim 12, wherein the
semi-tubular tabs are extended at the distal portion by an area for
longitudinal positioning of the link rod when the guiding device is
placed in the head of the bone anchor element, said area comprising
a transverse channel having an inner section at least equal to the
diameter of the link rod.
15. The guiding device according to claim 12, wherein the inner
section of the semi-tubular tabs comprises a widened area extending
out of the longitudinal recess when the device is placed in said
recess.
16. The guiding device according to claim 12, wherein the outer
section of the semi-tubular tabs comprises a shoulder arranged
configured to abut with the head of the anchor element.
17. The guiding device according to claim 12, wherein the
semi-tubular tabs are extended in the distal direction by a conical
area configured to separate the flexible proximal area of the
surgical instrument inside of which said guiding device is
inserted.
18. The guiding device according to claim 12, wherein the
semi-tubular tabs are flexible and flared when inactive.
19. A system of surgical instruments including a surgical
instrument having one end for coupling to the head of a bone anchor
element and a longitudinal channel, the head of the bone anchor
element having a tapped longitudinal recess configured for
receiving a screw cap, said longitudinal recess leading into a
transverse channel configured to receive a link rod, said system
comprising a guiding device including a rod for guiding the
surgical instrument, with a longitudinal axis A, having one end
comprising two semi-tubular tabs in which the outer section matches
the inner section of said longitudinal recess and in which the
inner section is at least equal to the diameter of the rod, the
cross-section of the guiding device being always smaller than the
section of the longitudinal channel of the surgical instrument in
order to allow the insertion and removal of said device in the
distal direction.
20. The system of surgical instruments according to the claim 19,
wherein said surgical instrument has, at the end thereof, two arms
each having a shoulder extending transversely over the inner
surface of the arm, said shoulder being capable of fastening to a
matching recess provided on the head of the bone anchor
element.
21. The system of surgical instruments according to claim 19,
wherein said arms of the surgical instrument are flexible and in
that said guiding device has a frusto-conical area configured to
separate said flexible arms when the guiding device is inserted
into said surgical instrument.
22. The system of surgical instruments according to claim 19,
wherein the guiding device and the surgical instrument are made at
least partially by polymer injection for single use.
Description
BACKGROUND
[0001] 1. Technical Field of the Invention
[0002] The invention relates to the field of surgery, specifically
to the field of installing bone implants having a head provided
such as to receive a screw cap and, where appropriate, an accessory
such as a link rod.
[0003] The invention relates specifically to a device for guiding a
surgical instrument into position on the head of a bone anchor
element having a tapped longitudinal recess intended for receiving
a screw cap, said longitudinal recess leading into a transverse
channel capable of receiving a link rod, the surgical instrument
having one end for coupling to the head of said bone anchor element
and a longitudinal channel.
[0004] 2. State of the Art
[0005] The placement of a link rod in a head of a bone anchor
element remains a rather complicated operation, since the rod is
often offset (in terms of height and/or laterally) relative to the
head of the bone anchor element. It is thus sometimes necessary to
resort to complementary instruments in order to place the link rod
in said head of the anchor element.
[0006] An example of such an instrument is described in patent
application WO2005/099602, which discloses a surgical instrument
intended for pushing a link rod into a spinal implant.
[0007] Also known from U.S. Pat. No. 6,440,133 is a surgical
instrument for reducing a rod into a bone anchor element. The
instrument includes an element that engages with the bone anchor
element, said engaging element having a distal portion suitable for
receiving a portion of the link rod, a reducing element arranged in
a mobile fashion about the element engaging the bone anchor element
and an actuator pivotably coupled with the element engaging the
bone anchor element and pivotably coupled to the reducing element,
the actuator making it possible to move the reducing element such
that the latter comes into contact with the link rod and to move
the latter towards the bone anchor element. The element engaging
the bone anchor element includes a pair of flexible arms and a tab
on the distal end of each of the flexible arms, each of said tabs
defining a channel for receiving the link rod inside thereof.
[0008] However, said instruments each have a major defect which is
the positioning on the head of the anchor element. Indeed, accurate
positioning is necessary in order to ensure correct attachment
between the instrument and the anchor element, which requires a
careful gesture. The tissues surrounding the surgical incision
actually impede access to the head of the anchor element and
sometimes make it impossible to install these instruments given the
constitution thereof. Placement is made even more difficult by the
fact that the heads of the anchor elements used are mobile most of
the time.
SUMMARY
[0009] The invention aims to solve these problems by providing an
instrument that makes it possible to guide a guiding device while
ensuring the positioning of the link rod relative to the head of
the bone anchor element, whether the head of a stationary or
multiaxial element head.
[0010] The invention also relates to providing a guiding device
that facilitates the installation of the surgical instrument on the
head of the bone anchor element.
[0011] The invention, in the broadest sense thereof, relates to a
device for guiding a surgical instrument having one end for
coupling to the head of a bone anchor element and a longitudinal
channel, the head of the bone anchor element having a tapped
longitudinal recess intended for receiving a screw cap, said
longitudinal recess leading into a transverse channel capable of
receiving a link rod, characterised in that said guiding device
includes a rod for guiding the surgical instrument, with a
longitudinal axis A, having one end comprising two semi-tubular
tabs in which the outer section matches the inner section of said
longitudinal recess and in which the inner section is at least
equal to the diameter of the link rod, the cross-section of the
guiding device being always smaller than the section of the
longitudinal channel of the surgical instrument in order to enable
the insertion and the removal of said device in distal
direction.
[0012] The guiding device thus arranged makes it possible to guide
the surgical instrument on the head of the bone anchor element but
also to realign the link rod longitudinally with the head of the
anchor element.
[0013] When the head of the element is mobile, the guiding device
makes it possible to position the head in a position in which the
tissues surrounding the incision do not impede the surgical
deed.
[0014] Said tabs advantageously have a cross-section that fits into
the space defined between the tapped inner wall of said
longitudinal recess, and the plane parallel to the median
longitudinal plane, crossing the surface of the link rod when the
latter is positioned in said transverse channel.
[0015] The inner section of the semi-tubular tabs is preferably
arranged such as to allow longitudinal positioning of the rod when
the device is inserted in the longitudinal recess. According to a
specific embodiment, the semi-tubular tabs are extended at the
distal portion by an area for longitudinal positioning of the link
rod when the guiding device is placed in the head of the bone
anchor element, said area comprising a transverse channel having an
inner section at least equal to the diameter of the link rod.
[0016] According to a specific embodiment, the inner section of the
semi-tubular tabs comprises a widened area extending beyond the
longitudinal recess when the device is inserted in said recess.
Said widened area ensures a lateral clearance of the link rod,
which facilitates the surgical deed by not requiring a perfectly
aligned position between the link rod and the head of the anchor
element.
[0017] The outer section of the semi-tubular tabs advantageously
comprises a shoulder arranged such as to abut with the head of the
anchor element. This provides a visual and tactile indication of
the correct placement of the guiding device in the head of the bone
anchor element.
[0018] According to a specific embodiment, the semi-tubular tabs
are extended in the distal direction by a conical area capable of
causing the separation of the flexible proximal end of a surgical
instrument inside of which said guiding device is inserted.
[0019] According to another embodiment, the semi-tubular tabs are
flexible and flared when inactive. This makes it possible to
provide a function of snap-fitting the guiding device onto the head
of the bone anchor element, and thus temporary holding of the
latter on said head.
[0020] The invention also relates to a system of surgical
instruments including a surgical instrument having one end for
coupling to the head of a bone anchor element and a longitudinal
channel, the head of the bone anchor element having a tapped
longitudinal recess intended for receiving a screw cap, said
longitudinal recess leading into a transverse channel capable of
receiving a link rod, characterised by also including a rod for
guiding the surgical instrument, with a longitudinal axis A, having
one end comprising two semi-tubular tabs in which the outer section
matches the inner section of said longitudinal recess and in which
the inner section is at least equal to the diameter of the link
rod, the cross-section of the guiding device being always smaller
than the section of the longitudinal channel of the surgical
instrument in order to enable the insertion and the removal of said
device in distal direction.
[0021] Said surgical instrument advantageously has, at the end
thereof, two arms each having a shoulder extending transversely
over the inner surface of the arm, said shoulder being capable of
fastening to a matching recess provided on the head of the bone
anchor element.
[0022] According to a specific embodiment, said arms of the
instrument are flexible, and said device has a frusto-conical area
capable of causing the separation of said flexible arms when the
guiding device is inserted into said surgical instrument. This
therefore facilitates the placement of the surgical instrument on
the head of the bone anchor element.
[0023] According to another advantageous embodiment, the guiding
device and the surgical instrument are made at least partially by
polymer injection for single use.
[0024] The guiding device is intended to be supplied as part of a
kit of instruments described in application WO2011/080426.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Further objectives and advantages of the invention will
become apparent from the following description made in reference to
the appended drawings, wherein:
[0026] FIG. 1 is a view of the guiding device according to a first
invention and a bone anchor element;
[0027] FIG. 2 shows the guiding device in position on the bone
anchor element;
[0028] FIG. 3 is a section view along the axis of the guiding
device of FIG. 2;
[0029] FIG. 4 is a longitudinal section view of the guiding device
according to the invention;
[0030] FIGS. 5 to 7 show the placement and removal of the surgical
instrument on the bone anchor element;
[0031] FIG. 8 shows the guiding device according to another
embodiment of the invention, said guiding device being ready to be
positioned on the bone anchor element.
DETAILED DESCRIPTION
[0032] In relation to FIGS. 1 to 7, the invention describes a
device 1 for guiding a surgical instrument 5 on a bone anchor
element 2 according to a first embodiment, said instrument 5 having
one end 50 for coupling to the head 3 of the bone anchor element 2
and a connecting longitudinal channel 51.
[0033] In the implemented embodiment, the head 3 of the bone anchor
element 2 has a tapped longitudinal recess 30 intended for
receiving a cap which can be screwed (not shown). The head 3 of the
bone anchor element 2 also comprises a transverse channel 31
leading into the longitudinal recess 30, said transverse channel 31
being capable of receiving a link rod 4.
[0034] In the described embodiment, the guiding device 1 includes a
guiding rod 6, with a longitudinal axis A, intended for guiding the
surgical instrument 5 when placed on the head 3 of the bone anchor
element 2, and two semi-tubular tabs 7, 8 arranged at one of the
ends 60 of the guiding rod 6.
[0035] The two semi-tubular tabs 7, 8 are shaped such as to have an
outer section S1 that matches the inner section S2 of the
longitudinal recess of a part and an inner section S3 at least
equal to the diameter D of the link rod 4. Furthermore, as will be
explained hereinafter, the guiding device 1 is configured such as
to have a cross-section that is always smaller than the section of
the longitudinal channel 51 of the surgical instrument 5 in order
to allow the insertion and the removal of the guiding device 1 in
the distal direction.
[0036] The term "distal" is understood to refer to the portion or
the end of an element that is furthest from the bone anchor element
2, while the term "proximal" is understood to refer to the portion
or end of the element that is closest to the bone anchor element
2.
[0037] Advantageously, the semi-tubular tabs 7, 8 have a
cross-section that fits into the space defined between the tapped
inner surface of the longitudinal recess 30 and the plane parallel
to the median longitudinal plane, crossing the surface of the link
rod 4 when the latter is positioned in the transverse channel 31
(FIG. 3).
[0038] In order to facilitate the removal of the guiding device 1
once the surgical instrument 5 is in place on the head 3 of the
bone anchor element 2, it has been provided to size the
semi-tubular tabs 7, 8 such as to leave a slight clearance 10
between the tabs 7, 8 and the inner surface of the longitudinal
recess 30 and between the tabs 7, 8 and the surface of the link rod
4. For this purpose, according to a preferred configuration, the
semi-tubular tabs 7, 8 have a distance of 5.5 millimetres measured
between the respective inner surfaces thereof (standard diameter of
the rods) and a distance of 7.5 millimetres measured between the
outer surfaces thereof. The semi-tubular tabs 7, 8 are obviously
not limited to these dimensions, which may be revised according to
the dimensions of the link rods and the rods of the bone anchor
elements used.
[0039] In the example shown in FIG. 3, the outer surface 70, 80 of
the semi-tubular tabs 7, 8 is rounded, while the inner surface 71,
81 thereof is planar. According to an alternative embodiment, it
can also be provided for the inner surface of the tabs to have a
concave shape, the tabs thus having a profile with a semi-circular
section.
[0040] The semi-tubular tabs 7, 8 are advantageously extended at
the distal portion thereof by an area for longitudinal positioning
11 of the rod when mounting the guiding device 1 on the head 3 of
the bone anchor element 2. The longitudinal positioning of the link
rod 4 is defined relative to the axis A of the latter. The
longitudinal positioning area 11 comprises a transverse channel 12
having an inner section S4 at least equal to the diameter of the
link rod 4. The transverse channel 12 of the longitudinal
positioning area 1 is such that when the guiding device 1 is
mounted on the head 3 of the bone anchor element 2, the
semi-tubular tabs 7, 8 and the positioning area 11 define with the
head 3 of the bone anchor element 2 an oblong slot 13 extending
according to the longitudinal axis AA (FIG. 2).
[0041] The positioning area 11 advantageously has an inner section
S4 that is larger than the diameter D of the link rod 4. This
widening of the section with regard to that of the semi-tubular
tabs 7, 8 has the advantage of allowing a lateral clearance of the
link rod 4 and thus of limiting the force to be applied to said rod
4 in order possibly to reposition same aligned with the transverse
channel 31 during the placement of the guiding device 1 in the head
3 of the bone anchor element 2.
[0042] The outer section S1 of the semi-tubular tabs 7, 8
advantageously comprises a shoulder 14 arranged such as to abut
with the upper surface 32 of the head 3 of the bone anchor element
3. The term "upper" is defined herein relative to the position of
the bone anchor element 2 in the figures. In the example shown, the
shoulder 14 defines the semi-tubular tabs 7, 8 of the longitudinal
positioning area 11 of the rod. Thus, as shown in FIG. 2, the
positioning area 11 extends beyond the longitudinal recess 30 of
the bone anchor element 2 when the guiding device 1 is mounted in
the head 3 of the bone anchor element 2.
[0043] According to another embodiment, it can be provided for the
shoulder to abut with a chamfer made at the entrance of the
longitudinal recess 30 of the head 3 of the bone anchor element
2.
[0044] According to a specific configuration, the semi-tubular tabs
7, 8 are flexible and flared when inactive. This has the advantage
of making it possible to retain the guiding device 1 once the
latter is in position in the head 3 of the bone anchor element 2,
this embodiment lacking the previously described clearance 10.
[0045] The semi-tubular tabs 7, 8 are advantageously connected
together by a joining portion 15 to which the guiding rod 6 is
secured. In the example shown in FIG. 4, the guiding rod 6 is
secured to the joining portion 15 of the semi-tubular tabs 7, 8 by
means of a part forming a tenon 16 arranged on the joining portion
15 and a portion forming a mortice 17 formed at the end 60 of the
guiding rod 6. Advantageously, the portions that form the tenon and
mortice 16, 17 are configured such that the guiding rod 6 and the
semi-tubular tabs 7, 8 are assembled by force. In order to
reinforce the securing of the guiding rod 6 to the semi-tubular
tabs 7, 8, it is possible to glue all or part of the portions
forming the tenon and mortice 16, 17.
[0046] Advantageously, the portion forming a tenon 16 of the
joining portion 15 comprises flattened areas capable of engaging
with flattened areas arranged on the inner surface of the portion
forming a mortice 17 of the guiding rod 6. This arrangement has the
advantage of preventing the rotation of the semi-tubular tabs 7, 8
relative to the guiding rod 6.
[0047] The assembly is such that once assembled the two elements
cannot be taken apart.
[0048] It is obvious that the two elements can be assembled by any
means known to a person skilled in the art without departing from
the framework of the invention.
[0049] FIGS. 5 to 7 show the steps of placing a surgical instrument
5, provided in the form of a tube, on the bone anchor element 2
(FIGS. 5 and 6) and then of removing the guiding device 1 once the
surgical instrument 5 is in position on the head 3 of the bone
anchor element 2 (FIG. 7). In the example shown, the surgical
instrument 5 comprises two flexible arms 52, 53 connected to one
another at the distal portion by means of a sleeve 54 and arranged
relative to one another in order to define a longitudinal channel
51 connecting on either side of the ends of the instrument 5, said
channel being capable of receiving the guiding rod 6 of the guiding
device 1. Each arm 52, 53 has a shoulder or any equivalent element
(pin, lug, etc.) extending transversely towards the longitudinal
channel 51, said shoulder being capable of being fastened in a
recess or cavity with a matching shape provided on the head 3 of
the bone anchor element 2.
[0050] In order to facilitate the placement of the surgical
instrument 5, according to another embodiment shown in FIG. 8, a
guiding device 1 may be provided in which the semi-tubular tabs 7,
8 are extended in the distal direction by a frusto-conical area 18.
The frusto-conical area 18 is arranged such as to be flared in the
proximal direction. This conical area 18 causes the separation of
the flexible proximal area of the surgical instrument 5 into which
said guiding device 1 is inserted when the surgical instrument 5
passes over the conical area 18.
[0051] The cone advantageously has a base with a section larger
than the outer section of the arms of the surgical instrument 5.
Thus, when the arms are slid along the guiding rod 6, the
frusto-conical area 18 gradually separates the arms 52, 53 of the
surgical instrument 5. The slightly separated position of the arms
52, 53 of the surgical instrument 5 thus obtained when said
instrument reaches the position for snap-fitting onto the head 3 of
the bone anchor element 2 facilitates the snap-fitting of said arms
52, 53 onto the head 3 of the bone anchor element 2.
[0052] The guiding device 1 and the surgical instrument are
advantageously made at least partially by polymer injection for
single use.
[0053] In the preceding embodiment, the guiding device 1 according
to the invention includes two separate elements: a first element
made up of the guiding rod 6 and a second element made up of the
semi-tubular tabs 7, 8. In this embodiment, the guiding rod 6 is
advantageously made of a polymer, while the semi-tubular tabs 7, 8
are made of metal.
[0054] The invention may, however, provide for a guiding device 1
in which the guiding rod 6 and the semi-tubular tabs 7, 8 are
formed integrally without thereby departing from the framework of
the invention.
[0055] The invention is described above as an example. It is
understood that those skilled in the art are capable of creating
different alternative embodiments of the invention without
departing from the framework of the invention.
* * * * *